In deadly Nepal flash floods, mango tree saves man; he says, ‘Wall of water came thundering down as if...’

As flash floods tore through Nepal on Wednesday, water, mud and rock came roaring down, and a mango tree became the unlikely saviour of a Nepali man digging a toilet pit outside a newly built house.

Bibek Kumal, 24, was working in Bidur near Nepal's border with Tibet when a massive “wall of water” swept him away.

His four co-workers shouted at him to get out and run, but fled before he scrambled out of the five-foot-deep (1.5-metre) pit, Reuters reported.

"I started running. Then a wall of water came thundering down as if it were an earthquake," Kumal said from his bed at Kathmandu's National Trauma Centre, where his brother Dinesh sat beside him.

Clinging to the mango tree, Kumal watched the house vanish.

Police later rescued him, though he suffered injuries to his right leg after being struck first by water and a large stone. His own home elsewhere escaped damage, he said.

"Luckily, I was stuck up in a mango tree. Had there been no mango tree, I would have been washed away to death," he said.

Three others injured in the flood were also being treated in Kathmanduas more victims were brought to the capital.

Cause of Nepal flash floods

While scientists are trying to find the exact reason behind the deadly flash floods, what’s clear so far is that a huge chunk of a glacier collapsed and that a 5.2 magnitude seismic event occurred at around 8:37 am local time on Wednesday, which in turn led to a catastrophic flow of debris downstream, the US Geological Survey (USGS) said.

The flood, triggered after what appeared to be the collapse of a mass of mud and rock into a river on the frontier between Nepal and Tibet, devastated settlements and infrastructure downstream.

The USGS first reported a magnitude 4.4 earthquake early Wednesday, about 66 kilometres (41 miles) north of Kathmandu, near the border.

The USGS later updated its analysis to say the seismic event it measured was a magnitude 5.2 glacial collapse that sent debris flowing downstream with catastrophic impact on communities.

It said its determination was based on data from nearby seismic stations, long-period seismic waves and satellite imagery, and that no earthquake had occurred.

“What we’ve certainly confirmed – there was a large ice avalanche, probably a mixture of ice and rock, which detached and then became fluid and then transformed into this devastating flood,” Simon Allen, a research associate at the University of Zurich who studies glacial hazards in the Himalayas, told Bloomberg.

Nepal flood death toll

The flash flooding near the Nepal-China border has claimed as many as 165 lives, while more than 1,300 are reported to be missing in one of Nepal's worst disasters.

The National Disaster Risk Reduction and Management Authority in Nepal said 826 people were missing and the death toll from the country’s flash floods rose to 165 on Thursday.

Meanwhile, Chinese state broadcaster CCTV separately reported that 260 of the 558 missing people in Tibet were foreigners, and two villagers were rescued. At least three people were killed as of Thursday morning, it said.